This disclosure relates generally to portable electronic devices, and specifically to battery powered mobile devices. In particular, the disclosure relates to sealing structures for the battery assembly, as related to overall battery size, energy density and form factor.
Batteries come in a range of different architectures and forms, including traditional rod-and-tube (dry cell) and flat plate (flooded cell) designs, and more advanced “jelly roll” configurations in which the anode and cathode layers are laid down on opposite sides of a flat sheet or flexible substrate, coated with a liquid or gel electrolyte, and rolled up for insertion into a cylindrical battery case, which is then sealed at either end. In flat battery designs, the anode and cathode structure may be folded inside a low-profile casing or pouch, which is sealed along one or more opposite sides. Where the seal or “tail” structure is folded over the top of the battery, as in typical existing designs, it may increase battery height or thickness. Alternatively, where battery thickness is constrained, a tail structure folded over the top of the battery reduces the available volume for energy storage.
Battery configurations for portable electronics and mobile devices require a range of design tradeoffs, including size, weight, power consumption, manufacturability, durability and thermal loading. Each of these factors impacts overall storage capacity and energy density, as defined by the amount of useful energy that can be delivered per unit volume or mass. The battery form factor (or package shape) is also an important design consideration, particularly for compact portable and mobile devices where space is at a premium. At the same time, effective sealing and insulating mechanism are also required, in order to provide high energy density and service life with improved durability leakage prevention.